VIRUS ISOLATED FROM SAN DIEGO, LONG BEACH AND LOS ANGELES AREA
By WILLIAM McD. HAMMON, M.D.
Professor oj Epidemiology, George William Hooper Foundation, Medical Center, San Francisco, California
In 1945 a rabies virus was isolated by the author from the brain of a horse from the Long Beach area which had supposedly died of equine encephalomyelitis. Peculiar properties which this virus exhibited made its identification difficult, but this was fmally accomplished by immuno- logical means. Its behavior was described to Dr. Harold Johnson, who found it similar to that of the rabies virus isolated from vampire bats and inquired whether it were possible that the horse was bitten by a vampire bat and whether these were found in Southern California. Dr. Johnson suggested that the horse might have been in Lower California, where vampire bats are known to occur, but no such history was obtained. Furthermore, this horse was a race horse, and the owner had no knowl- edge of its having been bitten by any canine.
Dr. Edwin Lenette of the California State Health Department isolated a virus from the brain of a giraffe from the San Diego zoo which also had some peculiar qualities suggestive of the vampire bat type of virus rabies. This giraffe had been in a mire fenced enclosure, and it was im- possible for any dog to enter; it would have been possible, however, for a rodent.
These experiences suggest the possibility that a form of rabies was present in Southern California that was not transmitted by dogs and had the characteristics of vampire bat rabies; the question was also raised whether some vampire bats might have been present in the area, al- though none had been reported. (Human beings infected with vampire bat rabies do not always die, and recovery with certain residual paraly- sis is not uncommon.) There is suggestive evidente that rabies trans- mitted by rodents does occur and that this may have happened in the Long Beach and San Diego areas to a horse and a giraffe respectiveIy.
The theory that rodents actually do transmit rabies has been chal- lenged, but this is certainly a field where more research is necessary. It is also agreed that if rabies were transmitted by rodents, it might be a different type of rabies virus than that transmitted by dogs.
VIRUS R.kBICO AISLADO EN LONG BEACH, CAL. (Sumario) En 1945 el A. ais16 un virus r&bico del cerebro de un caballo procedente de Long Beach, Cal., cuya muerte se había atribuído a encéfalomielitis equina.
El virus aislado se comportó como el virus de vampiros, sin comprobarse que’ el caballo hubiera estado expuesto a vampiros ni a animales caninos. El hallazgo
rwa PoLIoMYELITIs 367
por el Dr. Lenette de un virus parecido en una jirafa del Parque ZooMgico de San Diego, hizo pensar en la posibilidad de que exista en el sur de California una forma de rabia no transmitida por perros, con características similares a la rabia de los vampiros. AIgunos investigadores han sugerido la existencia de rabia en los roedores, que pudieran haber originado los dos casos citados. Sin embargo, esta teoría necesita aun de mayores investigaciones.
POLIOMYELITIS-SAN ANTONIO AREA-
A report by the Epidemiologid Committee, Sun Antonio City Health Department
The “Fiesta de San Jacinto,” a festival week devoted to indoor and outdoor entertainment, was held in San Antonio, Texas, from April 22 to April 27, 1946. Following this festival there appeared an abrupt outbreak of poliomyelitis. From the first of January to the 6rst of May only one case of poliomyelitis had been reported to the City Health Department in San Antonio. This case was reported early in January. On May 6, the first case of this outbreak was reported to the City Health Department. For the week ending May 11, ten cases were reported for the City and Bexar County; three of these died-two residents of t.he City and one of the county. On May ll, the Board of Health placed a ban on the City, prohibiting public gathermgs for those under the age of twenty-two years. On May 12, members of the State Department of Health and the City Board of Health met and discussed the entire situa- tion in the City of San Antonio and Bexar County. Following this meeting an Epidemiological Committee was set up to aid and advise in the clean-up and attempted control of the disease.
The Committee, in formulating its recommendations for the preven- tion of poliomyelitis, carefully considered the known faets relating to the characteristics of the virus causing the disease and the available data regarding its possibIe methods of transmission. Briefly stated, the following were considered:
1. The virus is destroyed by pasteurisation, i.e., by exposurc to a temperature of 55” C. for 30 minutes.
2. It resista drying for at least one month.
3. It survives in gastro-intestinal secretions for at lesst two houra.
4. It sur-vives in butter for at lea& three months; in milk for at lea& thirty-one days at room temperature; and in vrater for st lea&, three months at room tempera- ture.
5. Break point chlorination of water destroys the virus.